Party-line telephone apparatus.



v Patented A pr. 22, |902. G. MLLER. Y PARTY LINE TELEPHoNE APPARATUS.

, (Application :Bled Sept. 20, 1901.) v

' 2 Sheets-'Sheet I.

2s JZ qu Mum.)

'No.1 693,307/ f Patented Apu-22,1902.'

G *MLLEILYj PARTY L'IN'E'TEL'EPHUME APPARATUS.

(Application md '35pm-2o, 1901A.) (No Model.) j m m zsheets-sshaet2.l

THE Nomm PETERS cc, Puofaufuo.. wAsmNtroN. o. c,

UNITEDg STATES 4nrnN'r OFFICE.

GEoRGjlvIL-LER, or ooPENHAeEN, DENMARK.'

PARTY-LINE TELEPHONE APPARATl-JS.

SPECIFICATION forming part of Letters Patent No. 698,307, dated Apr122,1902. Application filed September 2,0, 1901. Serial No. 75,677.(Nolmodel.)

To all whom 7115 may concern: l

Be it known that I, GEORG MLLER, a subject of the King of Denmark,residing at Nordre Frihavnsveg A, Copenhagen, in the Kingdom ofDenmarlghave invented a new and Improved Party-Line Telephone Apparatus,of which the following is a specification.

My invention relates to improvements in` party-line telephone apparatus,the objectY being to provide a simple arrangement Whereby severalsubscribers are enabled to employ a single line to the central officeand Whereby such subscribers may be connected either with othersubscribers on the same line or with such subscribers Whose lines leadto the same central office. The central office connects the calling Withthe called subscriber, no subscriber'being able to connect himself Withanother or to disturb the connection ofl a speaking subscriber Withoutthe intervention of the central cnice.

The present arrangement differs from similar apparatus heretoforedevised in so far as every subscriber is enabled to communicate directlywith the central oce Without the intervention of a mediate station andin so far as the ordinary substation-battery 'of every subscriber isused for the purpose of cutting out all other lines, whereby theemployment of a special battery is' dispensed with.

My improved'apparatus comprises ,broadl y, four relays-to wit, aconnecting-relay, a disconnecting-relay, a blocking-relay, and anauxiliary blocking-relay.

Furthermore, my apparatus can be used in conjunction with the telephonedevices at present in use Without necessitating any change Whatever insuch devices.

The invention will be'more fully described hereinafter andv the novelfeatures pointed out in the appended claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification in which similar characters of reference indicatecorresponding parts in all the gures.

Figure l is a ldiagram of the circuits for an ordinary telephonerapparatus and for my improvedy apparatus. Fig. 2 is a side elevationFig. Ltis said, essentially four relays, two of which (theblocking-relay ce and the auxiliary blockingrelay y) are connected bycircuits 9 and 8, Fig. l, With the main line 72 and are energized bycurrent supplied from the central station. For the purpose of energizingthe blocking-relay either an alternating or a direct current can beemployed. The blockingrelay is so constructed or proportioned thatv itwill be operated by an alternating or direct current having a minimumstrengthof one milliampere. The auxiliary blocking-relay, on the otherhand, can be energized by direct current, having a minimum strength ofone milliampere, regardless of the direction of the current; but vsaidrelay cannot be operated by an alternating current of less than twentymilliamperes, because the tongue of the relay (to be hereinafterdescribed) has not sufcient time for vibration. The connecting anddisconnecting relays .z and/U are energized by direct current passingthrough a local circuit, said current being supplied by the usualsubstation-battery, as will hereinafter more fully appear.

To the right of Fig. l the circuits of the usual telephone apparatus areshown, and to the left of Fig. l the circuits and apparatus forming thesubject of the present invention are represented.

For the purpose of explaining the arrangement and operation of thedevices comprising the present invention, let it be assumed that asubscriber rings up the central station. Such ringing up is effected inthe usual manner by turning the crank of the magneto 34 and bysimultaneously pressing a push-button l, situated at some convenientplace on the booth containing the auxiliary telephone apparatus. Thecorresponding annunciatordrop at the central station Will thereby beactuated in the usual manner. At the same time all other subscribers onthe same lin'e will be 'cut out by means of the magneto-current flowingthrough `the blocking-relay x. Subscribers who have thus been cut outwill be informed by visible signals that the line is busy. Theblocking-relay of the calling subscriber is, however, not influenced byreason of the fact lthat the lower end ot' the button l glides over theupper portion of the indicator-arm 33 to prevent the blocking-relay fromattractingits armature. From the magneto 34 the current passes to thebindingpostE K ofthe ordinary telephone apparatus, which binding-post isconnected by an outer circuit 2 with the binding-postE K ot theauxiliary apparatus. From the binding-post EK the current passes throughthe circuit 3 to the contact-springe and through the contact 5, againstwhich the spring 6 is pressed by depressing the button 1. Thence thecurrent passes to the spring 6 and throughthe circuit 7 to thebinding-post Ll ot' the auxiliary apparatus, with which the outercircuit is connected. The current returns to the central station by wayof the said outer circuit through the annunciator-drop and to thebinding-post L of the auxiliary apparatus through circuits S and 9 andcontact 10 to circuit 11 through thebinding-post T L of the auxiliaryapparatus and through the circuit 12 to thebindingpostLofthetelephoneapparatus. Thencethe current passes by wayofthe circuit 13 to the telephone-hook la and through the contact 15,spring 16, and circuit 17 to the other pole of the magneto. Thus thecentral station is rung up and the other subscribers simultaneously cutoff.

The lnanner in which the subscribers are allcut oit will now bedescribed.

The magneto-current generated by the calling subscriber passes throughthe bindingpost L of the auxiliary apparatus, the circuits S and 9, thecontact 10, (the path formed by line 1l, binding-post T L', the., notconstituting a circuit,) the circuit 18, and the blocking-relay to thecircuit 10, thence through the contact 2O and circuits 2l and 37, thelatter of which terminates at the binding-post L ot the auxiliaryapparatus and from the said binding-post to the other outer circuit. Theblocking-relay a: will thereby be caused to attract its armature,whereby contact at 22 will be made and simultaneously contact at 10interrupted. When contacthas been made at the point 22, the current fromthe substation-battery flowing from the binding-post B of the auxiliaryapparatus, (said binding-post being connected by circuit 23 with apositive pole of the substation-battery 73,)` will pass through circuit2-1, contact 20, circuit 19, the blocking-relay, circuit 18, contact 22,and circuit 25 to the binding-post B of the auxiliary apparatus, saidbinding-post being electrically connected by circuit 2b' with thenegative pole of the substation-battery. The current from the saidbattery is thereby caused to pass through the blocking-relay to energizethe same and cause its armature to remain in attracted position.- Sincecontact at the point 10 is broken, it follows that the outercircuitisdisconnected from the bindingpostT L', so that the entire telephoneapparatus is cut out from the outer circuit. As the armature ot theblocking-relay is attracted the indicator will be moved into theposition indicated by dotted lines in Fig. 1, remaining in this positionuntil the armature of the blocking-relaya; returns to its normalunattracted position. The calling subscriber has now connected himselfwith the central station, cut out all other subscribers on the samelino, and given a signal to show that the line is busy. None of thecut-out subscribers can now be connected with the calling subscriber,the upper portion ot' the indicator-arm 33, as indicated by dottedlines, being swung into the path of the button. The contact-point ofthebutton cannot therefore be swung downward, i

and the spring 6, as a result, cannot be depressed. The central stationnow places the calling subscriber in communication with the subscribercalled. Should the called subscriber be located upon some other lineconnected at the central station, the two lines are connected at thecentral station in the usual manner. When the conversation has ended,the subscribers ring off, as usual, and disconnection is then eii'ectedat the central station, precisely in the same manner as in ringing up,by the depression of the button 1 and the turning of the magneto-crank.The button is automatically raised by the spring G after eachdepression. In order to reestablish connection with the cut-oftsubscribers, the central station will now send a positive impulse from acentral-station battery through the binding-post L/, circuit S,auxiliary blockingrelay y, (which is a polarized relay of highselt-induction,) and through the circuits 27, 24:, 21, and 37 to thebinding-post L of Athe auxiliary apparatus. By reason of its peculiarconstruction the auxiliary blocking-relay will not be energized by thepreviously-passed magneto-current, but only by the impulse sent from thecentral station, its tongue being thereby swung out against the contact2S. When contact has thus been made, the substation-battery Willinfluence the disconnecting-relay 'U in the manner now to be described.From the positive pole of the said battery the current passes throughcircuit 23, bindingpost B ot' the auxiliary apparatus, circuits 24 2129, disconnecting-relay V, circuit30, contact 28, tongue 3l of theauxiliary blockingrelay y, circuit 25, binding-post B' of the saidauxiliary apparatus, and finally through circuit 26 to the negative poleofthe substationbattery to attract the armature ot thedisconnecting-relay. The armature of `the disconconnecting-relay 'uhaving been attracted contact at the point 2O will be broken by means ofthe rod 32, connected with the said armature. The rod 32 carries a clamp75, Figs. 2 and 4, for an arm 76, serving to press the contact 2Oagainst the disk Pressure IOC) IIO

on the contact 20 is relieved immediately upon moving the rod 32,ytogether with the clamp and the arm. By this breaking of the contactthe current passing from the substationbattery through theblocking-relay is cut off, 'whereby the armature of `the said relay willAcircuits 27 24 21 37, to the binding-post L,

and to the positive pole of the battery at the central station. Theauxiliary blocking-relays are all energized, whereby contact isestablished at the point 36. The circuits through thesubstation-batteries will then be closed by the making of these contactsthrough the medium of the connecting-,relays, the current passing fromthe positive pole of the substation-battery through circuit 23,binding-post B, circuit 24, circuit 21, connecting relay c, circuit 38,contact 36, tongue 31, circuit 25, binding-post B', and circuit 26 tothe negative pole of the substation-battery. lThe relay uwill not beenergized unless the tongue 3l, under the influence of the current,moves to make contact at the point 28. The connecting-relays a' will nowattract their armatures, the ratchetwheels 49 rotating through thedistance of one tooth for each impulse sent from the central station.-Said disk 49 is rigidly connected with the disk 39, the position ofwhich determines the numbers of the subscribers. In- Figs. 1 and 4 thetelephone apparatus of subscriber No. 4 is represented. The stop 40 andthe notch 41 in the periphery of the disk 39 will operate in thefollowing manner after the ratchet 49 has been moved forward by fourteeth: The stop 40 presses upon the stop 42, whereby the spring ispressed against the screw 77 in such a manner that contact 43 is closed,whereby the centrall station is enabled to energize the bell. The notch41 will lie opposite the stop 40. By reason of the tension of thecontact-spring the stop 44 will fall into the said notch, wherebycontact 2O will be broken, the spring no longer engaging thecontact-screw.

This arrangement is particularly shown in Figs. 2 to 5. The contact-disk39 is mounted on the same shaft as a ratchet 49, located above theconnecting-relay a'. The armature of said relay is provided at its upperportion with a fork 50, Fig. 5, mounted to turn on the armature. Whenthe armature of the connecting-relay is influenced, the fork will movein the direction of the arrow 51, Fig. 5, so that the pallet 52 willengage the teeth of the ratchet-49 and will rotate the said v ratchet bythe distance of one-halfa tooth,r

the oppositely-situated*pallet 53 being simultaneously disengagedfromthe ratchet.v By reason of the retrograde movement of the armature thepallet 53 is again causedto engage the ratchet, but this time abovethe-next tooth, so that the ratchet is again turned through the distanceof one-half a tooth. For every impulse sent 'from the central-stationbattery the connecting-relay will be energized to a degree correspondingto a certain part of an entire revolution of the ratchet. Whenthedisconnecting-relay o attracts its armature, the rod 32, Figs. 2 and 4,will cause the fork to assume the position shown in dot-' ted lines, sothat the pallet 53 will be disengaged from the ratchet 49. and so thatthe ratchet, together with the contact-disk,will be returned by thecoiled spring 54 to its initial position. f

It' the central station should, for example, call up subscriber No. 4,four direct-current impulses will be sent through the circuitspreviously designated. The contact43, Figs.' 1 and 4, will thereby beclosed and contact 20` of the apparatus of subscriber No.4 will bebroken, while the opposite effect will bel produced at the apparatus ofthe other subscribers wherever these two contacts are inV their initialpositions, although the'ratchetapparatus will be blocked or cut oft`when the impulses are sent out bythe centralfstation. Said blocking orcutting off is eected precisely in the same manner as hereinbeforedescribed. By closing the contact at the point 43 the bell 35 ofsubscriber No. 4 will be electrically connected with the outer circuitin such a manner that when an alternating current is sent through thecircuitfrom the central station it flows through the following circuitand rings the bell: The alternating current flows through the outercircuit to the binding-post L', circuits .8 and 9, contact 10,(connected with circuit 9,) the armature of the relay circuit11,bindingpost T L,-circuit 12, binding-post L of the telephoneapparatus, circuit 13, telephone-receiver hook 14, contact 15, spring16, contact 17, short-circuit contact 45 yof the magneto 34 and the bell35, binding-post E K of the ordinary apparatus, circuit 46a resistance47 of one thousand ohms, circuit 48, contact 43, cir

cuits 21, and the binding-post L" of the auxiliary apparatus, and thusback to the central station. Since the resistance of 4the bell is aboutthree hundred ohms and the resistances of the relay :r and the relays yare respectively fifteen hundred and two thousand ohms, and since thebell is connected in parallel with the latter relay, the aforesaidresistance of one thousand ohms serves to produce an electrical balance.If, therefore, the bell resistance were greater, the resistance of onethousand ohms could be correspondingly dimin- IIO ished. It is evidentthat when the contact 2O of the apparatus of subscriber No. 4 is brokenthe blocking-relay :c cannot close the circuit from thesubstation-battery and that the contact l0 ot' the said apparatus cannotbe broken.

It a. subscriber wishes to converse with a subscriber not on the sameline, but on a line leading to the same central station, and for thispurpose rings up the central station,he must hold the button l indepressed position until a current is sent through the circuit of thecalled subscriber in order to operate the proper apparatus in ringing upthe called subscriber. When the called subscriber has been rung up, thecalling subscriber is automatically notified thereof by the simultaneousringing of his bell. Not until his bell has ceased to ring may thecalling subscriber release the button l.

In Figs. 6, '7, and S the auxiliary blockingrelay hereinbei'orementioned is pictured in detail. Said relay is a polarized relay and,like the blocking-relay, is surrounded with a thick iron jacket in orderto increase the seltinduction. The relay y is a horseshoe-magnetprovided with a winding. The post 65 carries the armature G6 and servesas a support for the magnets 67 and 68. It is a peculiarity 'of thisarmature that in its construction two springs 69 70 are so balanced thatthe tongue 3l, secured to the armature 66, can be held between thecontacts 28 and 36. It is evident that if a direct current is sentthrough these relays one ot` the contacts at the points 2S 36, dependingupon direction of the current, will be made by means of the tongue 3l,while, on the other hand,

contact cannot be made through the influence of an alternating current.When the relays are not energized, no contact is made. In order torender this relay still less sensitive to an alternating current and inorder still further to increase the self-induction, thc magnetic circuitis closed through the crosspiece 7l.

Having thus described my invention, I claim as new and desire .to secureby Letters Patentl. A party-line telephone apparatus, coinprisingconnecting relays for establishing talking-circuits between thestations, disconnectingrelays for disestablishing said circuits,blocking-relays for cutting out divers stations from said circuits, andauxiliary blocking-relays for cutting other stations into said circuits.

2. A party-line telephone apparatus, coinprising connecting relays forestablishing talking-circuits between stations, disconnecting-relays fordisestablishing said circuits, blocking-relays for cutting out diversother stations from said circuits, auxiliary blocking-relays for cuttingsaid divers other stations into said circuits, and means controllable atwill whereby a calling subscriber can simultaneously render hisownblocking-relay inactive and give warning to divers stations that theline is busy.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

GEORG MLLER.

W'itnesses z CHARLES IIUDE, MARCUS MLLER.

